Increasing competition in the casual gaming sector, particularly Ms. Kardashian’s new mobile game: “Kim Kardashian: Hollywood,” took a toll on Candy Crush, said Deutsche Bank, which downgraded the stock Wednesday morning to hold from buy and slashed its price target to $12 from $27.

“King’s second-quarter saga started with a bang but ended with a whimper,” Lloyd Walmsley, a research analyst at Deustche Bank, wrote to clients. He titled his research note: “Kim Kardashian, the King Slayer.”

“Competition within casual gaming is intense,” he added, “with Kim Kardashian: Hollywood and 2048 going after the same demographics.”

Shares fell as much as 23% to $13.97 Wednesday on heavy trading volume. The stock is down about 38% from its $22.50 IPO price earlier this year.

That’s not a good sign for King Digital, which late Tuesday reported quarterly revenue that fell short of Wall Street’s expectations. Bookings from “Candy Crush” declined more than expected, which prompted King to lower its revenue targets for the rest of the year.

“2014 is a year of transition moving toward the more diverse revenue base as we introduce new games to our audience,” King Digital CEO Riccardo Zacconi said on a conference call Tuesday evening with analysts.

The worry is that transition may not be such a smooth one.

“New games, despite steady presence in the top grossing charts, missed” estimates, Deutsche Bank said, which played a role in the firm’s downgrade.